Forest surveys and wildfire assessment in the Los Alamos Region; 1998-1999

To better understand the structural characteristics of vegetation in the Los Alamos region, the authors conducted two years of field surveys and associated analyses. This report introduces field methods, lists the summarized field data, and discusses the results of preliminary spatial analyses. During 1998 and 1999, seventy-six terrestrial plant communities were sampled for topographic characteristics, soil surface features, and vegetational conditions. A nested, randomized design was used to select the plot locations and to guide the sampling of the plot. The samples included a variety of fuel types, including surface fuels and ground fuels, shrubby and small tree fuels, and overstory fuels. Species composition data were also collected. The fuels data were summarized by vegetation type and evaluated for the topographic and spatial relationships of major field categories. The results of these analyses indicate that many of the fuels categories depend on topographic factors in a linear and curvilinear fashion. In particular, middle elevations within the Los Alamos region tend to support more surface fuels and ground fuels, whereas large-diameter trees are most dense at higher elevations and are specific to community types at these elevations. Small-diameter trees occur in more dense stands at lower and middle elevations and on specific soil and topographic conditions. Areas that burned in 1954 were found to be relatively free of fuels. The implications are that the western portions of the Los Alamos region are at risk from wildfire during dry, summer periods